Systems and methods for employing flexible graphite for thermal control of information handling resources

ABSTRACT

A system may include a thermal source, a thermal sink, and heat-rejecting media comprising flexible graphite thermally coupled between the thermal source and the thermal sink and configured to transfer heat from the thermal source to the thermal sink.

TECHNICAL FIELD

The present disclosure relates in general to information handlingsystems, and more particularly to cooling of information handling systemcomponents using flexible graphite as heat-rejecting media.

BACKGROUND

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

As processors, graphics cards, random access memory (RAM) and othercomponents in information handling systems have increased in clock speedand power consumption, the amount of heat produced by such components asa side-effect of normal operation has also increased. Often, thetemperatures of these components need to be kept within a reasonablerange to prevent overheating, instability, malfunction and damageleading to a shortened component lifespan. Accordingly, air movers(e.g., cooling fans and blowers) have often been used in informationhandling systems to cool information handling systems and theircomponents.

To control temperature of components of an information handling system,an air mover may direct air over one or more heatsinks thermally coupledto individual components. Traditional approaches to cooling componentsmay include a “passive” cooling system that serves to reject heat of acomponent to air driven by one or more system-level air movers (e.g.,fans) for cooling multiple components of an information handling systemin addition to the peripheral component. Another traditional approachmay include an “active” cooling system that uses liquid cooling, inwhich a heat-exchanging cold plate is thermally coupled to thecomponent, and a chilled fluid is passed through conduits internal tothe cold plate to remove heat from the component.

Employing liquid cooling in information handling systems, particularlyservers, is challenging. The liquid flow required may necessitatelarge-diameter tubes with little room for routing such tubes. Thermalcoupling to information handling resources may also be difficult, oftenrequiring thick and rigid copper components.

Existing servers may include a rigid fluid delivery system which oftenrequires 30 to 60 minutes to change a processor. Further, current memorycooling solutions employ a liquid tube through the memory componentswhich requires increased memory module pitch, thus decreasing density.

SUMMARY

In accordance with the teachings of the present disclosure, thedisadvantages and problems associated with traditional approaches tocooling information handling system components may be substantiallyreduced or eliminated.

In accordance with embodiments of the present disclosure, a system mayinclude a thermal source, a thermal sink, and heat-rejecting mediacomprising flexible graphite thermally coupled between the thermalsource and the thermal sink and configured to transfer heat from thethermal source to the thermal sink.

In accordance with these and other embodiments of the presentdisclosure, a method may include thermally coupling heat-rejecting mediacomprising flexible graphite between a thermal source and a thermal sinkin order to transfer heat from the thermal source to the thermal sink.

In accordance with these and other embodiments of the presentdisclosure, an assembly may include compliant material andheat-rejecting media comprising flexible graphite, wherein the compliantmaterial and the heat-rejecting media are arranged such that when thecompliant material is engaged with the heat-rejecting media, theheat-rejecting media is thermally coupled to at least one of a thermalsink and a thermal source.

Technical advantages of the present disclosure may be readily apparentto one skilled in the art from the figures, description and claimsincluded herein. The objects and advantages of the embodiments will berealized and achieved at least by the elements, features, andcombinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description andthe following detailed description are examples and explanatory and arenot restrictive of the claims set forth in this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments and advantagesthereof may be acquired by referring to the following description takenin conjunction with the accompanying drawings, in which like referencenumbers indicate like features, and wherein:

FIG. 1 illustrates a block diagram of an example information handlingsystem, in accordance with embodiments of the present disclosure;

FIG. 2A illustrates an exploded isometric view of an example liquidcooling assembly, in accordance with embodiments of the presentdisclosure;

FIG. 2B illustrates an assembled isometric view of the example liquidcooling assembly depicted in FIG. 2A, in accordance with embodiments ofthe present disclosure;

FIG. 3A illustrates a cross-sectional side view of an example liquidcooling assembly thermally coupled to adjacent memory modules, inaccordance with embodiments of the present disclosure;

FIG. 3B illustrates a cross-sectional side view of another exampleliquid cooling assembly thermally coupled to adjacent memory modules, inaccordance with embodiments of the present disclosure;

FIG. 4 illustrates an isometric view of selected components of aninformation handling system, including heat-rejecting media comprising aheat spreader portion and a heat bridge section thermally coupledbetween a device and a fluidic conduit of a liquid cooling system, inaccordance with embodiments of the present disclosure;

FIG. 5 illustrates a cross-sectional side view of selected components ofan information handling system, including a heat bridge section ofheat-rejecting media thermally coupled to a fluidic conduit, inaccordance with embodiments of the present disclosure;

FIGS. 6A-6C illustrate an isometric view of an example liquid coolingassembly at various stages of installation, in accordance withembodiments of the present disclosure;

FIG. 7A illustrates an auxetic structure that may be formed inheat-rejecting media, in accordance with embodiments of the presentdisclosure;

FIG. 7B illustrates the auxetic structure shown in FIG. 7A underpressure or tension, in accordance with embodiments of the presentdisclosure;

FIG. 8 illustrates example heat-rejecting media including auxeticstructures wherein the heat-rejecting media thermally couples andmechanically conforms to a component, in accordance with embodiments ofthe present disclosure;

FIG. 9A illustrates an example module having components to whichheat-rejecting media including auxetic structures may be thermallycoupled, in accordance with embodiments of the present disclosure; and

FIG. 9B illustrates example heat-rejecting media including auxeticstructures that may be scored therein, in accordance with embodiments ofthe present disclosure.

DETAILED DESCRIPTION

Preferred embodiments and their advantages are best understood byreference to FIGS. 1 through 9B, wherein like numbers are used toindicate like and corresponding parts.

For the purposes of this disclosure, an information handling system mayinclude any instrumentality or aggregate of instrumentalities operableto compute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize any form of information, intelligence, or data for business,scientific, control, entertainment, or other purposes. For example, aninformation handling system may be a personal computer, a PDA, aconsumer electronic device, a network storage device, or any othersuitable device and may vary in size, shape, performance, functionality,and price. The information handling system may include memory, one ormore processing resources such as a central processing unit (CPU) orhardware or software control logic. Additional components of theinformation handling system may include one or more storage devices, oneor more communications ports for communicating with external devices aswell as various input and output (I/O) devices, such as a keyboard, amouse, and a video display. The information handling system may alsoinclude one or more buses operable to transmit communication between thevarious hardware components.

For the purposes of this disclosure, computer-readable media may includeany instrumentality or aggregation of instrumentalities that may retaindata and/or instructions for a period of time. Computer-readable mediamay include, without limitation, storage media such as a direct accessstorage device (e.g., a hard disk drive or floppy disk), a sequentialaccess storage device (e.g., a tape disk drive), compact disk, CD-ROM,DVD, random access memory (RAM), read-only memory (ROM), electricallyerasable programmable read-only memory (EEPROM), and/or flash memory; aswell as communications media such as wires, optical fibers, microwaves,radio waves, and other electromagnetic and/or optical carriers; and/orany combination of the foregoing.

For the purposes of this disclosure, information handling resources maybroadly refer to any component system, device or apparatus of aninformation handling system, including without limitation processors,buses, memories, I/O devices and/or interfaces, storage resources,network interfaces, motherboards, integrated circuit packages;electro-mechanical devices (e.g., air movers), displays, and powersupplies.

FIG. 1 illustrates a block diagram of an example information handlingsystem 102, in accordance with embodiments of the present disclosure. Insome embodiments, information handling system 102 may comprise a serverchassis configured to house a plurality of servers or “blades.” In otherembodiments, information handling system 102 may comprise a personalcomputer (e.g., a desktop computer, laptop computer, mobile computer,and/or notebook computer). In yet other embodiments, informationhandling system 102 may comprise a storage enclosure configured to housea plurality of physical disk drives and/or other computer-readable mediafor storing data. As shown in FIG. 1, information handling system 102may include a chassis 100 housing a processor 103, a memory 104, adevice 116, and a liquid thermal control system 118.

Processor 103 may comprise any system, device, or apparatus operable tointerpret and/or execute program instructions and/or process data, andmay include, without limitation a microprocessor, microcontroller,digital signal processor (DSP), application specific integrated circuit(ASIC), or any other digital or analog circuitry configured to interpretand/or execute program instructions and/or process data. In someembodiments, processor 103 may interpret and/or execute programinstructions and/or process data stored in memory 104 and/or anothercomponent of information handling system 102.

Memory 104 may be communicatively coupled to processor 103 and maycomprise any system, device, or apparatus operable to retain programinstructions or data for a period of time. Memory 104 may compriserandom access memory (RAM), electrically erasable programmable read-onlymemory (EEPROM), a PCMCIA card, flash memory, magnetic storage,opto-magnetic storage, or any suitable selection and/or array ofvolatile or non-volatile memory that retains data after power toinformation handling system 102 is turned off.

Device 116 may comprise any component information handling system ofinformation handling system 102, including without limitationprocessors, buses, memories, I/O devices and/or interfaces, storageresources, network interfaces, motherboards, integrated circuitpackages; electro-mechanical devices, displays, and power supplies.

As shown in FIG. 1, liquid thermal control system 118 may include atemperature sensor 106, a control subsystem 124, heat-rejecting media122, pump 134, radiator 136, valve 130, fluidic conduits 126, andradiator control 140.

Temperature sensor 106 may be any system, device, or apparatus (e.g., athermometer, thermistor, etc.) configured to communicate a signal toprocessor 103 or another controller indicative of a temperature withininformation handling system 102. In many embodiments, informationhandling system 102 may comprise a plurality of temperature sensors 106,wherein each temperature sensor 106 detects a temperature of aparticular component and/or location within information handling system102. Although FIG. 1 shows temperature sensor 106 in thermalcommunication with fluidic conduits 126 in order to determine atemperature of fluid therein, it is understood that temperature sensor106 may appear in any suitable location within information handlingsystem 102.

Control subsystem 124 may be communicatively coupled to temperaturesensor 106, and may include any system, device, or apparatus (e.g., aprocessor, controller, etc.) configured to control components of liquidthermal control system 118 for increasing or decreasing a temperature ofone or more information handling resources of information handlingsystem 102. For example, control subsystem 124 may be configured tocontrol pump 134, valve 130, and/or radiator 136 based on thermal datasensed by temperature sensor 106, so as to maintain a safe operatingtemperature for one or more information handling resources. Accordingly,control subsystem 124 may include a pump control subsystem 127 forcontrolling operation of pump 134 (e.g., a pressure applied to coolantfluid in fluidic conduits 126 for moving such fluid through fluidicconduits 126), a valve load switch control subsystem 128 for controllingoperation of valve 130 (e.g., opening or closing valve 130, controllingan aperture of valve 130, etc.), and a radiator control subsystem 140for controlling operation of radiator 136 (e.g., enabling or disablingradiator 136, etc.).

Pump 134 may be fluidically coupled to one or more fluidic conduits 126and may comprise any mechanical or electro-mechanical system, apparatus,or device operable to produce a flow of fluid (e.g., fluid in one ormore conduits 126). For example, pump 134 may produce fluid flow byapplying a pressure to fluid in fluidic conduits 126. As describedabove, operation of pump 134 may be controlled by pump control subsystem127 which may control electro-mechanical components of pump 134 in orderto produce a desired rate of coolant flow.

Radiator 136 may include any device, system or apparatus configured totransfer thermal energy from one medium (e.g., fluid within a fluidicconduit 126) to another (e.g., air external to chassis 100) for thepurpose of cooling and heating. In some embodiments, radiator 136 mayinclude fluidic channels and/or conduits in at least a portion ofradiator 136. Such fluidic channels and/or conduits may be fluidicallycoupled to one or more of fluidic conduits 126 and pump 134. Asdescribed above, operation of radiator 136 may be controlled by radiatorcontrol subsystem 140 which may control components of radiator 136 inorder to produce a desired rate of heat transfer from the liquid withinfluidic conduits 126.

Valve 130 may include any device, system or apparatus that regulates,directs, and/or controls the flow of a fluid (e.g., a coolant liquid influidic conduits 126) by opening, closing, or partially obstructing oneor more passageways. When valve 130 is open, coolant liquid may flow ina direction from higher pressure to lower pressure. As described above,the operation of valve 130 (e.g., opening and closing, size of anaperture of valve 130) may be controlled by valve load switch controlsubsystem 128.

In operation, pump 134 may induce a flow of liquid (e.g., water,ethylene glycol, propylene glycol, or other coolant) through variousfluidic conduits 126 of information handling system 102, valve 130and/or radiator 136. As fluid passes by heat-rejecting media 122 in afluidic conduit 126 proximate to device 116, heat may be transferredfrom device 116 to heat-rejecting media 122 and from heat-rejectingmedia 122 to the liquid in fluidic conduit 126. As such heated liquidflows by radiator 136, heat from the liquid may be transferred from theliquid to air ambient to chassis 100, thus cooling the liquid.

Heat-rejecting media 122 may include any system, device, or apparatusconfigured to transfer heat from an information handling resource (e.g.,device 116, as shown in FIG. 1), thus reducing a temperature of theinformation handling resource. For example, heat-rejecting media 122 mayinclude a solid thermally coupled to the information handling resource(e.g., heatpipe, heat spreader, heatsink, finstack, heat fin, heatbridge, etc.) such that heat generated by the information handlingresource is transferred from the information handling resource. Asdescribed in greater detail below, in some embodiments, heat-rejectingmedia 122 may comprise a heat spreader, heat fine, or heat bridgecomprising flexible graphite shaped in a desired manner, or any materialhaving similar properties to flexible graphite, including apliability/flexibility at room temperature and a thermal conductivity atleast three times that of copper. Further as described in greater detailbelow, in some embodiments, heat-rejecting media 122 may comprise aheat-pipe comprising flexible graphite shaped in a desired manner. Insome embodiments, graphite comprising heat-rejecting media 122 may beanisotropic, with a thermal conductivity three times that of copperalong two axis of the graphite, but with poor thermal conductivity alongits third axis (e.g., thickness).

In addition to processor 103, memory 104, temperature sensor 106, device116, and liquid thermal control system 118, information handling system102 may include one or more other information handling resources. Inaddition, for the sake of clarity and exposition of the presentdisclosure, FIG. 1 depicts only one device 116. In embodiments of thepresent disclosure, information handling system 102 may include anynumber of devices 116. Furthermore, for the sake of clarity andexposition of the present disclosure, FIG. 1 depicts device 116including a liquid thermal control system 118 for cooling of device 116.However, in some embodiments, approaches similar or identical to thoseused to cool device 116 as described herein may be employed to providecooling of processor 103, memory 104, and/or any other informationhandling resource of information handling system 102.

FIG. 2A illustrates an exploded isometric view of an example liquidcooling assembly 200, in accordance with embodiments of the presentdisclosure. FIG. 2B illustrates an assembled isometric view of exampleliquid cooling assembly 200, in accordance with embodiments of thepresent disclosure. As shown in FIGS. 2A and 2B, liquid cooling assembly200 may include a carrier 202, heat-rejecting media 122A, and a portionof fluidic conduit 126. Carrier 202 may comprise any suitable material,and as shown in FIGS. 2A and 2B, may include a plurality of U-shapedchannels 204, each U-shaped channel 204 having opposing sidewalls linedwith a compliant material 206.

Heat-rejecting media 122A may comprise flexible graphite or anothermaterial having flexibility and similar thermal conductivity properties(e.g., at least three times thermal conductivity of copper) to that offlexible graphite. In some embodiments, heat-rejecting media 122Adepicted in FIGS. 2A and 2B may be used to implement heat-rejectingmedia 122 depicted in FIG. 1. As shown in FIG. 2A, heat-rejecting media122A may include features 208 for receiving fluidic conduit 126, whichthus may thermally couple heat-rejecting media 122A to fluidic conduit126. Also, heat-rejecting media 122A may include a plurality of U-shapedchannels 210, such that when assembled into liquid cooling assembly 200,U-shaped channels 210 of heat-rejecting media 122A may nest withinrespective U-shaped channels 204 of carrier 202.

In use, liquid cooling assembly 200 may press fit upon a plurality ofadjacent modules 300 (e.g., dual-inline memory modules or “DIMMs”), asshown in FIG. 3A, such that compliant material 206 may apply force uponheat-rejecting media 122A in order to thermally couple heat-rejectingmedia 122A to modules 300. In particular, the flexible nature ofheat-rejecting media 122A may allow heat-rejecting media 122A to, underthe force of compliant material 206, flexibly conform its shape to thatof the surfaces of modules 300, which may include memory chips and/orother structures, thus potentially maximizing thermal coupling betweenheat-rejecting media 122A and surfaces of modules 300. Accordingly, inoperation, heat generated by modules 300 may be transferred from modules300 to heat-rejecting media 122A, and from heat-rejecting media 122A toa cooling liquid within fluidic conduit 126, thus providing cooling tocomponents (e.g., memory chips) of modules 300.

FIG. 3B illustrates a liquid cooling assembly 200A slightly modifiedfrom liquid cooling assembly 200 shown in FIGS. 2A and 2B. As shown inFIG. 3B, fluidic conduits 302, which may comprise or may fluidicallycouple to fluidic conduit 126, may run inline and in parallel withmodules 300 when liquid cooling assembly 200A is engaged with modules300, and carrier 202 may apply force to heat-rejecting media 122A, suchthat heat-rejecting media 122A maintains thermal coupling with bothfluidic conduits 302 and modules 300, such that heat may transfer frommemory 300 to heat-rejecting media 122A to cooling liquid within fluidicconduits 302, thus providing cooling to components (e.g., memory chips)of modules 300.

FIG. 4 illustrates an isometric view of selected components ofinformation handling system 102, including heat-rejecting media 122Bcomprising a heat spreader portion 402 and a heat bridge section 404thermally coupled between device 116 and fluidic conduit 126, inaccordance with embodiments of the present disclosure. As shown in FIG.4, heat-rejecting media 122B may be arranged such that heat generated bydevice 116 may be transferred to fluidic conduit 126 via heat spreaderportion 402, then to heat bridge section 404 of heat-rejecting media122B. Heat spreader portion 402 may be mechanically and thermallycoupled to device 116 in any suitable manner, including via a thermalinterface material or other adhesive. As shown in FIG. 4, heat bridgesection 404 may be mechanically and thermally coupled to fluidic conduit126 via a clip 406 or other suitable fastener or securement.

FIG. 5 illustrates a cross-sectional side view of selected components ofinformation handling system 102, including heat bridge section 404 ofheat-rejecting media thermally coupled to fluidic conduit 126, inaccordance with embodiments of the present disclosure. As shown in FIG.5, heat bridge section 404 may terminate into a full or partialcylindrical shape termination 504 which may wrap around or otherwisemaintain contact with fluidic conduit 126. Thermal insulation 502 maysurround termination 504, thus providing thermal isolation betweentermination 504 and fluidic conduit 126 on one hand and an ambientenvironment on the other hand, thus potentially maximizing heat transferfrom heat bridge section 404 to fluidic conduit 126. As further shown,clip 406 may secure termination 504 to fluidic conduit 126 (and maysecure thermal insulation 502 to termination 504). Clip 406 may includean inherent spring force that maintains clip 406 in place, and in sodoing, maintains physical contact between termination 504 and fluidicconduit 126, thus potentially maximizing heat transfer from heat bridgesection 404 to fluidic conduit 126.

FIGS. 6A-6C illustrate an isometric view of an example liquid coolingassembly 606 at various stages of installation, in accordance withembodiments of the present disclosure. As shown in FIGS. 6A-6C, abackplane 600 (e.g., a motherboard or other printed circuit board) mayinclude a plurality of adjacent receptacle connectors 602, eachreceptacle connector 602 configured to receive a module 604 (e.g., amemory module) to mechanically and electrically couple the module tosuch receptacle connector 602 and backplane 600. Liquid cooling assembly606 may include a first portion 616 hingedly coupled to a second portion610. First portion 616 may include fluid fittings 614 configured tofluidically couple to fluidic conduit 126, and fluid fittings 614 may inturn be fluidically coupled to fluidic conduits 608 integral to liquidcooling assembly 606. First portion 616 may also include heat-rejectingmedia 122C formed in a plurality of U-shaped channels, such that fluidicconduits 608 thermally couple to heat-rejecting media 122C withinconcavities of such U-shaped channels. Second portion 610 may includecompliant material 612, which may also include a plurality of U-shapedchannels corresponding to the U-shaped channels of heat-rejecting media122C.

In order to engage liquid cooling assembly 606 to modules 604, liquidcooling assembly 606 may be positioned over modules 604 as shown in FIG.6A, and lowered onto module 604 as shown in FIG. 6B, with eachindividual concavity of the U-shaped channels lowered onto a respectivemodule 604, such that opposite parallel walls of each U-shaped channelscome in physical contact with a respective surface (e.g., memory chipsmounted to such surface) of a module 604. After liquid cooling assembly606 has been lowered onto modules 604 as shown in FIG. 6B, a user maymove second portion 610 from the open position shown in FIG. 6B to theclosed position shown in FIG. 6C. When lowered into the closed position,compliant material 612 may apply force to heat-rejecting media 122C,maintaining thermal coupling between heat-rejecting media 122C andmodules 606. In particular, the flexible nature of heat-rejecting media122C may allow heat-rejecting media 122C to, under the force ofcompliant material 612, flexibly conform its shape to that of thesurfaces of modules 604, which may include memory chips and/or otherstructures, thus potentially maximizing thermal coupling betweenheat-rejecting media 122C and surfaces of modules 604.

In some embodiments, a cross-sectional side view of liquid coolingassembly 606 engaged with modules 604 may appear similar to thatdepicted in FIG. 3C, described above.

To enhance mechanical and thermal coupling of heat-rejecting media 122to a heat-generating device 116, in some embodiments, heat-rejectingmedia 122 may include local mechanical structures formed therein toassist heat-rejecting media 122 to mechanically conform to aheat-generating device 116 to which it is coupled. For example, FIG. 7Aillustrates an example auxetic structure 700 that may be formed inheat-rejecting media 122, in accordance with embodiments of the presentdisclosure. FIG. 7B illustrates auxetic structure 700 under pressure ortension, in accordance with embodiments of the present disclosure.

Generally speaking, an auxetic structure may be a mechanical structurethat has a negative Poisson's ratio. When stretched, an auxeticstructure may become thicker perpendicular to the applied stretchingforce. This phenomenon may occur due to a particular internal structureor pattern. To illustrate, FIG. 7A depicts auxetic structure 700 withoutany external force or tension applied. As shown in FIG. 7A, auxeticstructure 700 may include a pattern of polygons 702 (e.g., squares)arranged with a pattern of polygonal voids 704 (e.g., non-squareparallelograms) formed therein. Although FIG. 7A depicts a particularauxetic structure 700, other auxetic structures may be used inaccordance with the present disclosure.

When a mechanical tension is applied to auxetic structure 700 (e.g., inthe horizontal axis of FIGS. 7A and 7B), auxetic structure 700 mayincrease in dimension in an axis perpendicular to the applied tension(e.g., in the vertical axis of FIGS. 7A and 7B).

FIG. 8 illustrates example heat-rejecting media 122D including auxeticstructures 700 wherein heat-rejecting media 122D thermally couples andmechanically conforms to a component 804 (e.g., a memory chip mounted toa module 802 in the form of a printed circuit board), in accordance withembodiments of the present disclosure. Heat-rejecting media 122D mayinclude a thin flexible material (e.g., with a thickness significantlysmaller than its other dimensions, so as to be practicallytwo-dimensional in nature), such as a thin, flexible graphite, andauxetic structures 700 may be formed therein in any suitable manner,including as described in further detail below. According, as a force isapplied to compliant material 806 mechanically coupled to heat-rejectingmedia 122D, auxetic structures 700 aligned with corners or otherfeatures of component 804 may conform a shape of heat-rejecting media122D to component 804, thus potentially increasing physical contact andthermal coupling between component 804 and heat-rejecting media 122D.

To illustrate how auxetic structures 700 may be formed in heat-rejectingmedia 122D, FIG. 9A illustrates module 802 (e.g., memory module) havingcomponents 804 (e.g., memory chips) to which heat-rejecting media 122Dincluding auxetic structures 700 may be thermally coupled, in accordancewith embodiments of the present disclosure. FIG. 9B illustratesheat-rejecting media 122D (having fluidic conduit 126 thermally andmechanically coupled thereto) including illustration of locations 900within heat-rejecting media which may be patterned (e.g., scored and/orcut) to form auxetic structures 700 (not explicitly shown in FIG. 9B),in accordance with embodiments of the present disclosure. Locations 900may correspond to (e.g., may be matched to) locations of particularfeatures (e.g., corners or edges) of components 804. In someembodiments, heat-rejecting media 122D may be scored without suchscoring penetrating through heat-rejecting media 122D, while in the sameor alternative embodiments, patterning may penetrate throughheat-rejecting media 122D.

Although FIGS. 7A through 9B and the discussion thereof pertain toforming auxetic structures 700 in heat-rejecting media 122D comprising aflexible graphite material, it is understood that the teachings of thepresent disclosure may apply to forming auxetic structures in othermaterial to enable such material to conform to a shape of anotherstructure to which such material may be mechanically coupled.

In operation, auxetic structures 700 may first fail when mechanicallystressed creating a localized area (e.g., an area under mechanicalstress) having a negative Poisson's ratio, while an area ofheat-rejecting media 122D not stressed may not fail. In other words,application of heat-rejecting media 122D including auxetic structures700 to a non-uniform surface may mechanically stress heat-rejectingmedia 122D, which may cause localized failures at auxetic structures700, allowing heat-rejecting media 122D to locally conform to shapeswith large deviations and non-uniformities.

In some instances, relief features (e.g., patterned features whichpenetrate through heat-rejecting media 122D) may be formed within areasof high stress concentration (e.g., corresponding with corners of acomponent 804).

In these and other embodiments, use of auxetic structures 700 or otherpatterned features may be minimized in order to maximize the thermalconductivity of heat-rejecting media 122D.

In these and other embodiments, heat-rejecting media 122D may includealignment features patterned therein to bias heat-rejecting media 122Dinto a desired alignment with a component 804.

In these and other embodiments, use of auxetic structures 700 or otherpatterned features may be formed using one or more of die cutting, laserablation, water jet, reel-to-reel manufacturing, and/or any othersuitable technique.

Although particular arrangements are depicted and described aboveshowing use of flexible graphite or a material with similar propertiesas heat-rejecting media, it is understood that other arrangements may beused in order to transfer heat from heat-generating components tocooling fluid within fluidic conduits of a liquid cooling system.

Although the foregoing contemplates using a clip or compliant materialto maintain physical contact between heat-rejecting media 122 and athermal source (e.g., an information handling resource) and a thermalsink (e.g., fluidic conduit), any other suitable system, device, orapparatus for supplying such force may be used, including a clamp,pressure from a compliant element, pressure applied by a secondaryprocess, a latching force, a ramped insert, mechanism activated througha cam during motion, a bi-stable latching mechanism, traditionalfasteners, bolts, clamps, etc.

In one or more embodiments of the present disclosure, heat-rejectingmedia 122 may include one or more features to improve serviceability ofinformation handling resources. In one or more embodiments of thepresent disclosure, such one or more features may include compliantfeatures that deform to secure heat-rejecting media 122 to and releaseheat-rejecting media 122 from a thermal source or thermal sink. In someof these embodiments, such compliant features may provide positivefeedback (e.g., audible clicks) that such compliant features areproperly installed. In these and other embodiments, such one or morefeatures may allow heat-rejecting media 122 to rotate about a thermalsink or a thermal source without disconnecting or removing the compliantmaterial from the heat-rejecting media 122.

In these and other embodiments, heat-rejecting media 122 may havecontinuous thermal coupling to or between one or more components. Forexample, in some embodiments, heat-rejecting media 122 may thermallycommunicate with one or more thermal sinks. As another example,heat-rejecting media 122 may be formed to ensure a face ofheat-rejecting media 122 in contact with a thermal source is the sameface of heat-rejecting media 122 in contact with a thermal sink. One ormore deformations of heat-rejecting media 122 may be used to form adesired shape of heat-rejecting media 122, including folding, bending,and twisting. As a further example, a portion of heat-rejecting media122 may be wrapped around a cylindrical thermal sink to maximize surfacearea between heat-rejecting media 122 and such thermal sink.

In some embodiments, heat-rejecting media 122 may include a “serviceloop” to improve serviceability and installation. For example, in someembodiments, heat-rejecting media 122 may have a length or shape toavoid other components.

Although not expressly described above, heat-rejecting media 122 may beincorporated into a hard drive carrier. For example, heat-rejectingmedia 122 may be in thermal contact with a hard drive when the harddrive is secured to the hard drive carrier. As another example, in someembodiments, installation of a hard drive carrier into an informationhandling system chassis may cause thermal contact of heat-rejectingmedia 122 to hard drives within the hard drive carrier. As a furtherexample, in these and other embodiments, a hard drive carrier mayprovide structure to support heat-rejecting media 122 and providemechanical pressure between heat-rejecting media 122 and other thermalcomponents. In such embodiments, such structure may have compliantmechanisms to provide positive confirmation (e.g., audible clicks) whenproperly installed.

In these and other embodiments, heat-rejecting media 122 may beincorporated within an information handling system chassis (e.g., withinhard drive bays, memory slots, etc.). Thus, instead of a carrierassembly including heat-rejecting media 122, heat-rejecting media 122may be located within the chassis of an information handling systemitself. For example, heat-rejecting media 122 may be incorporated on acomponent installed on a motherboard or backplane. As another example,heat-rejecting media 122 may be backed by a compliant layer, whereininstallation of an information handling resource causes the compliantlayer to move out of the way, and once the information handling resourceis installed, the compliant layer provides a pressure on heat-rejectingmedia 122 against the information handling resource. As a furtherexample, heat-rejecting media 122 may physically conform against theinformation handling resource using one of the mechanisms describedabove.

Among the advantages of heat-rejecting media 122 is that it may be usedto thermally cool information handling resources (e.g., memory modules,hard drives, riser cards, etc.) while minimizing their pitch for maximumcomponent density.

In addition, groups of components may be secured to heat-rejecting media122 such that that they may be installed and/or uninstalled as a singlecomponent. For example, memory modules may be stacked to minimize pitchwith a heat-rejecting media 122 in between adjacent memory modules, suchthat two or more memory modules may be installed or uninstalled at once.

In some embodiments, heat-rejecting media 122 may comprise multipleportions of heat-rejecting media 122 mechanically coupled together thatmay be conveniently coupled and decoupled from one another. Suchmechanism may provide a thermal “quick disconnect” feature allowing aninformation handling resource to be serviced. In some embodiments,portions of heat-rejecting media 122 may be clamped together to providea continuous thermal path. In such embodiments, installation of acomponent to be cooled may provide the clamping force.

The systems and methods described above may enable replacing a sectionof flexible tube with copper tube and securing heat-rejecting media 122to the copper tube to provide a mechanism for cooling components onservers previously designed. In such instances, heat-rejecting media 122may be secured and serviced via one or more mechanisms described above.In some embodiments, replacing small sections of a flexible tube maystill allow the tube to maintain desired flexibility.

In some embodiments, heat-rejecting media 122 may be combined with athermally isolating surface and/or thermal insulator to minimizeunintentional radiated and conducted heat from heat-rejecting media 122.For example, such thermal insulator may be applied to thermal and/ormechanical connection points or user touch points for servicing. Asanother example, a thermal insulator may be applied across a substantialportion of heat-rejecting media 122 to minimize heat transferred into aninformation handling system chassis. As a further example, a thermalinsulator may be applied across a substantial portion of heat-rejectingmedia 122 to prevent one information handling resource from warminganother information handling resource.

As used herein, when two or more elements are referred to as “coupled”to one another, such term indicates that such two or more elements arein electronic communication or mechanical communication, as applicable,whether connected indirectly or directly, with or without interveningelements.

This disclosure encompasses all changes, substitutions, variations,alterations, and modifications to the example embodiments herein that aperson having ordinary skill in the art would comprehend. Similarly,where appropriate, the appended claims encompass all changes,substitutions, variations, alterations, and modifications to the exampleembodiments herein that a person having ordinary skill in the art wouldcomprehend. Moreover, reference in the appended claims to an apparatusor system or a component of an apparatus or system being adapted to,arranged to, capable of, configured to, enabled to, operable to, oroperative to perform a particular function encompasses that apparatus,system, or component, whether or not it or that particular function isactivated, turned on, or unlocked, as long as that apparatus, system, orcomponent is so adapted, arranged, capable, configured, enabled,operable, or operative. Accordingly, modifications, additions, oromissions may be made to the systems, apparatuses, and methods describedherein without departing from the scope of the disclosure. For example,the components of the systems and apparatuses may be integrated orseparated. Moreover, the operations of the systems and apparatusesdisclosed herein may be performed by more, fewer, or other componentsand the methods described may include more, fewer, or other steps.Additionally, steps may be performed in any suitable order. As used inthis document, “each” refers to each member of a set or each member of asubset of a set.

Although exemplary embodiments are illustrated in the figures anddescribed below, the principles of the present disclosure may beimplemented using any number of techniques, whether currently known ornot. The present disclosure should in no way be limited to the exemplaryimplementations and techniques illustrated in the drawings and describedabove.

Unless otherwise specifically noted, articles depicted in the drawingsare not necessarily drawn to scale.

All examples and conditional language recited herein are intended forpedagogical objects to aid the reader in understanding the disclosureand the concepts contributed by the inventor to furthering the art, andare construed as being without limitation to such specifically recitedexamples and conditions. Although embodiments of the present disclosurehave been described in detail, it should be understood that variouschanges, substitutions, and alterations could be made hereto withoutdeparting from the spirit and scope of the disclosure.

Although specific advantages have been enumerated above, variousembodiments may include some, none, or all of the enumerated advantages.Additionally, other technical advantages may become readily apparent toone of ordinary skill in the art after review of the foregoing figuresand description.

To aid the Patent Office and any readers of any patent issued on thisapplication in interpreting the claims appended hereto, applicants wishto note that they do not intend any of the appended claims or claimelements to invoke 35 U.S.C. § 112(f) unless the words “means for” or“step for” are explicitly used in the particular claim.

What is claimed is:
 1. A system comprising: a thermal source; a thermalsink; heat-rejecting media comprising flexible graphite thermallycoupled between the thermal source and the thermal sink and configuredto transfer heat from the thermal source to the thermal sink; and athermal insulator coupled to the heat-rejecting media to minimize heattransfer from the heat-rejecting media.
 2. The system of claim 1,wherein the heat-rejecting media is configured to be mechanicallycoupled to at least one of the thermal source and the thermal sink viaan adhesive.
 3. The system of claim 1, wherein the heat-rejecting mediais configured to be mechanically coupled to the thermal source via aforce applied by the thermal sink.
 4. The system of claim 1, wherein thethermal sink comprises a fluidic subsystem of a liquid thermal controlsystem for providing thermal control of the system, the fluidicsubsystem configured to convey a liquid in order to transfer heat fromthe thermal source to the thermal sink via the heat-rejecting media. 5.The system of claim 1, wherein the heat-rejecting media is configuredto, when placed in contact with at least one of the thermal source andthe thermal sink, conform to at least one of a shape of the thermalsource and a shape of the thermal sink.
 6. The system of claim 1,wherein the thermal source comprises an information handling resource ofan information handling system.
 7. A method comprising: thermallycoupling heat-rejecting media comprising flexible graphite between athermal source and a thermal sink in order to transfer heat from thethermal source to the thermal sink and coupling a thermal insulator tothe heat-rejecting media to minimize heat transfer from theheat-rejecting media.
 8. The method of claim 7, further comprisingmechanically coupling the heat-rejecting media to at least one of thethermal source and the thermal sink via an adhesive.
 9. The method ofclaim 7, further comprising mechanically coupling the heat-rejectingmedia to the thermal source via a force applied by the thermal sink. 10.The method of claim 7, wherein the thermal sink comprises a fluidicsubsystem of a liquid thermal control system, the fluidic subsystemconfigured to convey a liquid in order to transfer heat from the thermalsource to the thermal sink via the heat-rejecting media.
 11. The methodof claim 7, wherein the heat-rejecting media is configured to, whenplaced in contact with at least one of the thermal source and thethermal sink, conform to at least one of a shape of the thermal sourceand a shape of the thermal sink.
 12. The method of claim 7, wherein thethermal source comprises an information handling resource of aninformation handling system.
 13. An assembly comprising: compliantmaterial; heat-rejecting media comprising flexible graphite, wherein thecompliant material and the heat-rejecting media are arranged such thatwhen the compliant material is engaged with the heat-rejecting media,the heat-rejecting media is thermally coupled to at least one of athermal sink and a thermal source; and a thermal insulator coupled tothe heat-rejecting media to minimize heat transfer from theheat-rejecting media.
 14. The assembly of claim 13, wherein the at leastone of the thermal sink and the thermal source comprises a fluidicsubsystem of a liquid thermal control system, the fluidic subsystemconfigured to convey a liquid in order to transfer heat from the thermalsource to the thermal sink via the heat-rejecting media.
 15. Theassembly of claim 13, wherein the compliant material and theheat-rejecting media are arranged such that when the compliant materialis engaged with the heat-rejecting media, the heat-rejecting mediaconforms to at least one of a shape of the thermal source and a shape ofthe thermal sink.
 16. The assembly of claim 13, wherein the thermalsource comprises an information handling resource of an informationhandling system.